Brake shoe lining machine



April 3, 1954 P. A. SCHNEBELEN 2,675,051

BRAKE SHOE LINING MACHINE Filed Oct. 29 1951 Patented Apr. 13, 1954 UNITED STATES PATENT OFFICE- BRAKE SHOE LINING; MACHINE Paul A Schnebelen, Toledo, Ohio Application October 29, 1951, SerialNo. 253,723

2 Claims.

This invention relates to servicing elements having. friction face regions or linings, as for clutches and brakes.

This invention has utility when incorporated in carrying thru for rapid and efficient bonding. by film or plastic of a lining facing on a metal shoe; while a worn or defective element may be speedily debonded with a resultant undistorted clean mounting to take on a new lining. Under the program herein there is immersion in a predetermined temperature controlled bath for a sufficient interval to fuse the film coating of a shoe. In the debonding, there is preferably predetermined a higher temperature to permit ready snapping of the worn lining clear of its mounting on a brake shoe face.

Referring to the drawings:

Fig. l is a. side elevation of a pair of brake shoes having their faces film coated and spread against a band in firm assembly for immersion arm control;

Fig. 2 is a side elevation, partly broken away, of a bath with controls for immersion bonding of the linings on the shoes of Fig. 1;

Fig. 3 is a perspective view of a lining bonded shoe from Fig. 2;

Fig. 4 is a side elevation, of a portion only, of an immersion bath for lining release in the debonding practice hereunder;

Fig. 5 is a side elevation of a brake shoe from the bath of Fig. 4, at the snap ofi operation for clearing the lining from the shoe;

Fig. 6 is a detail view in edge elevation of a snapped-off lining from the shoe of Fig. 5; and

Fig. 7 is a side elevation of the shoe of Fig. 5 as cleared of the lining and ready for relining.

In assembly, a film or coating I (Fig. 1) may be applied to a face 2 of a shoe 3. An appropriate section of lining 4 is placed thereon. For a pair of shoes, a flexible band 5 is extended about the shoes 3 holding the pair of linings 4 against the faces 2 of the two shoes. A strut or adjustable spread device 6 assembles the unit. Assembly means 1 at four spaced points on the pair of shoes connects the pair of shoes with a U-portion 8 from an arm 9 (Fig. 2).

The arm 9 is mounted on a fixed axis for rocking as actuated by a pinion ll engaged by a rack [2. A bracket l3 locates the arm 9 in overhanging position as to a molten pool [4. A

crucible 15 for the pool H has an insulation jacket IE to reduce heat loss. A burner I1 for the tank l has a gas supply duct I8 with a valve IS with connection l9 to a controller 20. Temperature responsive means in the tank pool M has connection 2| to the controller 20. A face of the controller 28 has an indicator 22 as to the temperature condition, while concentrically therewith is a time indicator 23. Under the general stop-watch principle, the timer 23 may be preset, as for 3 min. say for immersion to attachv the lining l by fusing the bonding agent I. The pre determined temperature feature of the control is maintained well in hand thru the selection. of the composition of the charge for the bath. With knowledge of the fusion point for the coating to be acted upon to bring to cohesion or release, the practice is that such is considerably above the boiling point of water, for brake linings currently are of asbestos or like material to retain its physical form to resist moisture and heat. The composition of metal, alloy, or even salt, may be taken as liquid at around 255 F. and for the factor of safety to retain fluidity during use, the temperature may be run up to as high as 350 F. Inasmuch as the problem here has to do with bonding and debonding, the distinct composition is not one of coating or recoating, but to leave the work clean of matter foreign to the fusible coating.

The bath may be a lead, bismuth, zinc, tin alloy as low as F. for fusion. The arm 9 holds the objects to be subjected to the bath immersed by down pressure. When some salts are used, the arm 9 acts to keep the work from sinking. The preferred practice is to have the work in the pool l4 away from the tank l5. With a tank heated up for operation, the work handled may be one at a time, or in gangs, with following sequence. The burner capacity, and pool [4 volume, should be such that for efiicient handling the pool temperature carries thru for quite a few degrees away from solidifying at all times for work immersion.

The predetermined time is preferably for such interval that uniform temperature may be set up thruout the body of the shoe 3. Then the con troller 2!] acts automatically thru the rack I2, pinion H and arm 9 to swing the work from the pool [4 at a slant or proper self-draining pitch.

Upon a lining 4 becoming worn, fractured or otherwise damaged, there is importance in salvaging of the shoe 3. While plural shoes 3 may be handled, for a single shoe 3, the arm 9 may have rigid therewith a portion 24 (Fig. 4) with connections I. The debonding temperature of the pool 14 may be in the range of 622. The batch of material to be molten in a pool 14 may be around 300# for a three gallon tank [5 and the temperature of the bath held in the range of 700 to 750 F. The controller 20 may be set to carry thru in the range of forty to forty-five seconds.

The bath M (Fig. 4) has the rapid superficial heating uniform thruout the entire shoe and lining 25 as worn. The drain-tilted-out shoe 3 is released from the arm means or support 9, 24. A hand tool or small prying instrument 26 may be given a slight hammer stroke at the end of the lining 25, and such at once snaps as a unit free and clear thruout of the facing 2 of the shoe 3. The shoe 3 is at once in condition for reassembly with a new lining 4 by being first coated with the bonding agent I.

What is claimed and it is desired to secure by Letters Patent is:

1. A brake shoe lining machine for bonding and debonding a lining to and from a brake shoe wherein a bonding agent coacts in the bonding and debonding, said machine respectively comprising: a support for a pair of brake shoes, an outer flexible clamping band about the pair of shoes, an adjustable spread device to hold the shoes against the band, means for fastening said shoes to said support, said support including a lever arm, a tank for holding a liquid bath of fusion-effective temperature for the bonding agent, and means connected to said lever for dipping the support carried brake shoes into said tank and lifting said support held shoes at an angle above said tank for draining, said last mentioned means comprising a gear and complementary toothed means engaging said gear, said lever being connected to said gear, and means for longitudinally moving said toothed means to immerse and lift said support carried brake shoes into and from said tank, respectively.

2. A machine according to claim 1 wherein said bonding agent between said linings and brake shoes comprises a thermoplastic agent, and wherein said bath is maintained at a temperature above the fusion of said agent and below the temperature of deterioration of said brake linings.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,128,722 Renisch Feb. 26, 1915 1,392,649 Tepak Oct. 4, 1921 1,595,811 Anderson Aug. 10, 1926 1,881,887 Normann Oct. 11, 1932 2,002,795 Przyborowski May 28, 1935 2,223,362 Federman Dec. 3, 1940 2,267,190 Claffy Dec. 23, 1941 2,417,468 Canziani et al Mar. 18, 1947 2,426,421 Tilden et al Aug. 26, 1947 2,550,758 Bemis May 1, 1951 2,609,310 Barrett Sept. 2, 1952 2,625,497 Cadgene Jan. 13, 1953 

